Applicare la formula: $a+b$$=a+b$, dove $a=-\frac{1}{4}$, $b=-\frac{18}{5}$ e $a+b=-0.25-3.6-4.2+8.6+1.05$

Applicare la formula: $a+b$$=a+b$, dove $a=-\frac{77}{20}$, $b=-\frac{21}{5}$ e $a+b=-3.85-4.2+8.6+1.05$

Applicare la formula: $a+b$$=a+b$, dove $a=\frac{43}{5}$, $b=-8.05$ e $a+b=-8.05+8.6+1.05$

Applicare la formula: $a+b$$=a+b$, dove $a=\frac{11}{20}$, $b=\frac{21}{20}$ e $a+b=0.55+1.05$